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Plate Material

Iron plates retain the fibrous quality imparted to the bar,
and are therefore much stronger in the direction of the fibre than
across it. Owing to the secretion of cinder and scale between
the layers during piling, the finished plate must be carefully
examined for faultsó(i) by eye, (2) by slinging from the four
corners and tapping, when the dull, ashy portions may be de-
tected by the non-vibration of sand sprinkled over the surface.



. 2.75.

JtoJUburvq MM Jb

Very bad plates are rejected, and the others placed in the scale
according to quality, thus evolving the various degrees of ' best,'
'double best,7 and 'treble best;' terms, however, by no means
sufficiently definite. The Yorkshire irons are made with great care
and a large expenditure of fuel, being also very carefully selected,
Steel Plates and Bars are rolled similarly. The ingots,
obtained as at pp. 79 to 8% .are, after casting, usually broken up,
piled, and re-heated, though spine ^authorities complain that this
destroys the homogeneity far which steel plates are admired, and
prefer to roll direct from the Ingot. The slubs or ingots should